That's very constructive indeed, w23. Many thanks everyone.
On a slightly different note but still on topic I hope, I am surprised that on this highly technical issue, standardisation and quality assurance don't seem to be what you would expect. I mean, other than reputation, what is stopping me from advertising a bog-standard cable from a pound shop as miraculously super-fast ADSL++++ grade? Even most of those who buy it won't be able to tell for sure.
